Fault Jumping Attacks against Shrinking Generator
Marcin Gomulkiewicz, Miroslaw Kutylowski
Wroclaw University of Technology
Pawel Wlaz
Lublin University of Technology
We concern security of shrinking generator against fault attacks.
While this pseudorandom bitstream generator is cryptographically strong and well suited
for hardware implementations, especially for cheap artefacts, we show that using it
for the devices that are not fault resistant is risky. That is, even if a device concerned
is tamper-proof, generating random faults and analyzing the results may reveal secret keys
stored inside the device.
For the attack we flip a~random bit and observe propagation of errors. The attack uses peculiar
properties of the shrinking generator and presents a new kind of threats for designs based
on combining weaker generators. In particular, it indicates that potentially all designs based
on combining LFSR generators might be practically weak due to slow propagation of errors
in a single LFSR.
appeared in ALGOSENSORS'2008